Cloud computing is one of the most promising technology which plays a key role in the next generation of computer technology. It has been broadly accepted due to its ability to fewer costs associated with computing while increasing scalability and flexibility for computer processes. Cloud computing provides a facility of data outsourcing, in which different data owner can upload data and different data user can access data. But, here the data should not be secure in the hands of cloud providers. Data owner have expressed concerns about the various security aspects that be present with the cloud computing.